﻿//
// (C) Copyright 2009 Irantha Suwandarathna (iranthas@hotmail.com)
// All rights reserved.
//

/* Copyright (c) 2001-2008, The HSQL Development Group
 * All rights reserved.
 *
 * Redistribution and use _in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * Redistributions _in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer _in the documentation
 * and/or other materials provided with the distribution.
 *
 * Neither the name of the HSQL Development Group nor the names of its
 * contributors may be used to endorse or promote products derived from this
 * software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;

namespace EffiProz.Core.Lib
{
    public class CountUpDownLatch
    {
        ManualResetEvent latch;
        int count;

        public CountUpDownLatch()
        {
            latch = new ManualResetEvent(false);
        }

        public void await()
        {

            if (count == 0)
            {
                return;
            }

            latch.WaitOne();
        }

        public void countDown()
        {

            count--;

            if (count == 0)
            {
                latch.Set();
            }
        }

        public long getCount()
        {
            return count;
        }

        public void countUp()
        {

            if (!latch.Reset())
            {
                latch = new ManualResetEvent(false);
            }

            count++;
        }

        public void setCount(int count)
        {

            if (count == 0)
            {
                latch.Set();
            }
            else if (!latch.Reset())
            {
                latch = new ManualResetEvent(false);
            }

            this.count = count;
        }

    }
}
